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Q & A: Is nothing something?

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Most recent answer: 07/06/2009
Q:
is nothing something?
- george (age 80)
brisbane qld ausralia
A:
This is actually a very interesting question.   First of all let me redefine the word 'nothing' as 'the vacuum' which is the modern term.   Before the development of quantum field theory and string theory the vacuum was really thought of as absence of air, matter or anything, i.e. nothing.   But when quantum field theory came along it was realized that the vacuum is really full of lots of quantum stuff.  Feynman showed that particle anti-particle pairs could exist in the vacuum.  It takes energy to pop them out, they don't come for free, but experiments have shown this to be true.  Other experimental phenomena, such as the Casimir effect show that there is is an attractive force between two conducting plates, even if they are not charged. 
  See:     
This force comes about from quantum field effects in the vacuum.  

There is a warning about this idea, however:  many charlatans have tried to invent perpetual motion machines and to bilk unwary people into investing money in 'zero point energy' schemes.  Fortunately the first Law of Thermodynamics also applies to the vacuum. 

LeeH




(published on 06/29/2009)

Follow-Up #1: nothing stuffing

Q:
What exactly lies between the nucleus and the nearest electron? It cannot be air, so is it vacuum? I think it would be an area fiiled with radiation. Still, it will be in vacuum. Would it mean that all stuff is made of nothing?
- Nimish (age 17)
Mumbai, India
A:
The electron does not exist as a dot at some point. It has a state which is spread out over the region of the atom. In many cases, the state includes a lot of 'electron-ness' right over the region occupied by the nucleus. In other cases, the state gets more intense away from the nucleus.

To the best of our knowledge, there's nothing around but the fields representing the electron, the nucleus, the photons, etc. The regions that we call 'vacuum' have nearly zero values for all those fields, except for the photon fields.

All stuff seems to be made of these fields. The fields as we know them may turn out ultimately to be made of some more fundamental fields. Whether there's something underneath all the fields that isn't itself a field, we don't know for sure.

Mike W.

(published on 07/06/2009)

Follow-up on this answer.